Arctic sea ice melt: a correlation with ENSO?

My first contact with Wayne Davidson was when reading his posts on RealClimate back in 2006, around the time when my interest in the Arctic was first awakened. His remarks often stood out for their first hand knowledge and their experimental way of thinking, like contemplating the influence of lunar spring tides on the Arctic sea ice, or a way of determining Polar amplification by optical atmospheric refraction, mainly using the sun as a baseline sphere. In fact his website, Extremely High Horizon Refraction, is mostly revolving around his study of the optical effect caused by atmospheric refraction during sunrises.

But Wayne Davidson, a meteorological observer who has been stationed in Resolute Bay (or Qausuittuq, 'the place with no dawn' as the Inuit call it) for 25 years now, writes about many more things pertaining to the situation in the Arctic and Global Warming, such as global weather conditions and predictions. This made me come back to his site every once in a while, as I like reading what other people think is going to happen in the short term.

Wayne's site had quite a bit to offer on this subject, including a very interesting theory that links the influence of ENSO (better known as El Niño and La Niña) to weather conditions in the Arctic that are crucial for the amount of ice and its general condition. Wayne Davidson has been developing this theory for a while now and started writing about it on his website from October 2008 onwards.

Anvil Seeding Theory

So how does this theory work? Well, it's a bit complicated for me to explain, being a not so knowledgeable layman when it comes to climatology or meteorology, but I'll try to communicate it as best as I can.

Basically it comes down to small particles, or 'anvil seeds' that influence the formation of clouds. These aerosols are shot upwards in the stratosphere by weather phenomena such as big cyclone thunderstorms and then transported to the Poles. Two things play a major role in this. First of all, ENSO has an influence on the amount of particles that are released from the oceans (El Niño for instance causes the upwelling of warmer water, which increases the evaporation of water that holds the cloud seeds), and determines the amount of convection to the stratosphere. The other factor is the Polar stratospheric vortex that is mostly active during winter and keeps the anvil seeds in suspension.

The interplay of these factors will determine the amount of clouds in the Arctic, and clouds as we all know play a very important role (together with winds, current and air/sea temperatures) in Arctic sea ice melt. According to Davidson there is a strong correlation between ENSO and Arctic melting. The effects of an El Niño are such that more clouds are formed over the Arctic, causing warmer winters (slow growth and thickening of ice) and cooler summers (less melting). With La Niña, the effects are reversed.

The details are scattered over Wayne Davidson's EH2r website, which I have collected in this document: Download Anvil.

What you see on the right is a picture of a cumulonimbus incus (incus is Latin for 'anvil), courtesy of the Danish Meteorological Institute

Wayne Davidson's prediction for the 2010 Summer melt

Davidson has been very clear from the start. In September 2009 he stated: "If El-Nino persists till the spring, and La-Nina follows, ships at the Pole will wander unobstructed in August 2010." He maintains this would cause the emergence of clear skies, or Big Blue as he calls it (which is a lovely term if only for the fact that it reminds me of the wonderful movie with the same title by Luc Besson).

On May 20th Davidson wrote:

La-Nina is all but a sure thing, with it comes bluer skies, as with Anvil seeding theory, the larger part of Equatorial Oceans are cooler, except from the much smaller but extremely warm Atlantic, less clouds will be spawned from fewer cloud seeds. Unlike 2007, much cooling occurred a few months later. This ensured a warm spring, coupled with clearer subsequent cloud free skies, pretty much everywhere in the world, but most acutely for the Arctic, which will now melt even faster.

So how about that La Niña? Well, the Australian Bureau of Meteorology released its ENSO Wrap-Up two days ago, stating:

Neutral conditions persist in the Equatorial Pacific Ocean. Sea surface temperatures in the central Pacific have cooled by around half a degree in the last month, but remain within neutral thresholds.(...) The majority of international computer models are forecasting continued cooling of the tropical Pacific to below La Niña thresholds in the coming months. Some current indicators are consistent with these forecasts.

No La Niña for the time being, but if Wayne Davidson is correct, these neutral conditions should also have considerable effects on cloudiness in the Arctic. Combined with the heavily fractured ice mass, the open Nares Strait, the low volume (there's currently some controversy over that one) and the record low sea ice extent for this date, a very blue Arctic, as Davidson puts it, might "see an onslaught of melting exceeding 2007".

We'll see how cloudy the Arctic will be this summer and if the Anvil seeding theory proves to be sufficiently reliable for further research. In the meantime Wayne Davidson is up there in Resolute Bay - 'the place where tomorrow never comes' - witnessing it all with his own eyes.

 

This last picture was sent to me and shot by Wayne Davidson. His explanation:

It shows Arctic air stratified structures with the help of the sun line multiplied 4 times, of which the top line is perhaps the first ever captured green flash, actually in the process of 'flashing'. The digital camera capture shows it red because its sensitive to infra-red light. Then again, through warming, these layers will disappear slowly as the air becomes more convective because air rises in warmer air instead of being trapped horizontally in colder Arctic air.

I'd like to thank Wayne Davidson for his suggestions and permission for this blog post.

Comments

[Kevin McKinney]

Interesting indeed, Neven. I've always been intrigued by Wayne's RC posts as well, but didn't know he was blogging on his own.

I didn't check out the link to the "controversy" you mention, but if it's the latest from Mr. Goddard about "extent vs. concentration," I read that and was singularly unimpressed. The one thing that everyone agrees on, it seems, is the obvious truism that time will tell.

On another topic, I note that IJIS didn't update yesterday; any idea "what's up with that?"

[Neven]

On another topic, I note that IJIS didn't update yesterday; any idea "what's up with that?"

No idea whatsoever, but it happened last year and the year before that as well. It might be due to the smoothing 'erroneous blip' between May 20 to June 11or perhaps they haven't received any (reliable) data. There are some gaps here and there. Let's see what happens. I was planning on writing a new SIE update tomorrow, or perhaps later today.

[Kevin McKinney]

Thanks! And the new SIE update made me smile--I've long thought that it would be good to have a piece--or more than one--about failed "realist" predictions. I've thought of "It's been cooling since WHEN?" but who knows if I'll get that written. It would take a fair bit of digging--or maybe not. . .